Work feeding mechanism for machine tools



March 12, 1935 E. R. sivuTH ET AL 1,993,754

WORK FEEDING MECHANISM FOR MACHINE TOOLS Filed NOV. 25, 1951 6 Sheets-Sheet l March 12, 1935. E. R. SMITH ET AL' I ,9 4 A WORK Famine MECHANISM FOR MACHINE TOOLS File'd Nov. 23', 1931 s Sheets-Sheet 2 March 12, 1935. R, sM|TH ET AL 1,993,754

WORK FEEDING MECHANISM FOR MACHINE TOOLS Filed NOV. 25, 1951 6 Sheets-Sheet 3 Mm 1 F as mu .P mm T 3 m L. lll HLl w 1 E E= 9 MN 7 Q Oh March 12, 1935. E, R, SMITH ET AL WORK FEEDING MECHANISM FOR MACHINE TOOLS Filed NOV. 23, 1931 6 Sheets-Sheet 4 H w N m 4/, v mw .w. f V

March 12, 1935.

E, R. SMITH ET AL v WORK FEEDING MECHANISM FOR MACHINE TOOLS Filed Nov. 23, 1951 6 Sheets-Sheet 5 fizz/17.2? div/2% fEarJm wha- QEM

March 12, 1935. E. R. SMITH El Al.

WORK FEEDING MECHANISM FOR MACHINE TOOLS Filed Nov. 25, 1931 e Sheets-Sheet 6 NNN l Patented Mar. 12, 1935 UNITED STATES warm PATENT OFFICE WonK FEEDING MECHANISM FOR MACHINE TOOLS of- Massachusetts Application November. 23, 1931, Serial No. 576,831

9 Claims.

This invention relates to lathes,grinding machines and other machine tools, and particularly to. mechanism for automatically inserting pieces of work in such. machines and'ior removing finished work therefrom.

More specifically, our'invention relates to the general type of work-feeding mechanism shown inthe prior patent to Smith and Schinkez No. 1,794,424, patented March 3, 1931.

It is the general object of our invention to provide a work-feeding orloading mechanism of improved construction, and to provide simplified operating mechanism therefor, which mechanisms are extremely reliable and satisfactory in use.

Our invention further relates to arrangements andv combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

Preferred forms of the invention are shown in the drawings, in. which :v

Fig. 1. is a front elevation of our improved feeding mechanism;

Fig. 2 is an end view thereof, looking in. the direction'of the arrow 2'in Fig; 1; I

Fig. 3 is. a plan view of; the mechanism with certain. parts removed, looking in the direction of the arrow 3 in Fig. 1;

Figs. 4, 5 and 6 are front elevations'showin successive positions of the work-feeding mechanism;

Fig. "I is anenlarged detailfront elevation of the devices for retaining the work on the loading platform or chute;

Fig. 8 is a plan View. of the mechanism. shown in Fig. 7;

Fig. 9 is a front elevation, partly in section, showing one pair of work grippers and the operating mechanism therefor, and

Fig. 10 is a side elevation of a modified construction. 7

Referring to the drawings, we have shown portions of an automatic lathe including a bed or frame 10, front and rear tool slides 11 and 12, a loading platform or chute 13, and an unloading or discharge runway 14, all of these parts being supported on the bed 10 and indefinite relation to gach other.

A frame'20' is mounted on the bed 10 and supports the loading and unloading devices to be described, together with their actuating mechanism. These devices and associated mechanisms are mounted on a carriage 22 (Fig. 2). slidable cross-wise of the machine onguide-ways 23 on the frame "This-transverse movement is preferably effected; by means of a piston 24 (Fig. 3') slidably mounted in a cylinder 25 and having its piston rod 26 extended outwardly through the end of the cylinder and provided with rack teeth engaging a pinion 27 on a cross shaft 28 mounted in fixed bearings on the frame 20. A spur gear 29 is mounted on theshaft 28 and engages a rack bar 30-on'the upper part of the carriage 22. I I

Air or other fluid under pressure is admitted through pipes 31 M22 to move the piston 24 in a desired-direction. When one pipe is connected to admit fiuid under pressure, the other pipe is connected to the/exhaust or atmosphere. Y.

The carriage 22 is -provided.- with laterally spaced vertical bearings 40 and 41 for a pair of plungers 42 and 43, provided withpairs of grippers 44' and 45 at their lower ends. The

plunger 42- is provided with: rack teeth, 47-, engaged by a spur gear 48 on a cross shaft 49 mounted in a bearing in-the'upper part of the carriage 22. The-shaft49 is provided with a pinion 50 (Fig. 3') engaged by rack teeth, on a piston rod 51 connected to a piston 52 slidable in a cylinder 53- and operated by air or other fiuidpressuresupplied through pipes 54 and 55 (Fig. 1). 7 4

When air is admitted through the pipe 54, the

plunger 42 is lowered, and-when ai-r isadmitted through the pipe 55 the plunger 42 is raised, it being understood that'the inoperative pipe in either case is connected to the atmosphere or exhaust.

'A fluid pressure cylinder is also provided, having air connections 61 and 62 and connected to operate'the plunger 43 through gear mechanism identical with that previously described for operating the plunger. 42. I

The details of construction of one pair of grippers and the operating mechanism therefor is shown in Fig. 9,-in which it appears that the grippers44 arepivoted at 63 and 64 to a head 65 secured to the lower end of the plunger 42. The plunger 42. is provided with an axial cylindrical recess 66 in which a piston 67 is slidable.

A piston rod 68 extends outward through the closed end of the recess or cylinder 66 and is provided with annular ribs 69 forming a circular rack, engaging segmental gear teeth 70 on the adjacent faces of the pivoted end. portions of the grippers 44, A spring '72 presses the piston 6'7 downward to open the grippers and a supply pipe '13 admits fluid under pressure to raise the piston and close the grippers when desired.

The construction of the operating mechanism for the grippers 45 is the same as the mechanism for the grippers 44 but the gripper head 75 for the grippers 45 is provided with a roll 76 (Fig. 1) engaging a ledge or shoulder 77 on the frame 20 for a purpose to be described.

The work-holding and releasing mechanism is shown in detail in Figs. 7 and 8, and is particularly designed for use with pieces of cylindrical work W such as automobile piston blanks.

Retailing arms 80 (Fig. '7) are secured to a cross shaft 31, pivoted in bearings at the lower end of the run-way or chute 13. These arms 80 extend upward into the path of the lowermost piece of work W; A spring 82 connected through an arm 83 to the shaft 81 holds the arms 80 normally in retaining position.

A second set of retaining arms 85 is secured to a second cross shaft 86, also pivoted in bearings in the runway 13 and provided with a de-' pending arm 8'? connected by a link 88 to a simv ilar depending arm 89 on the cross shaft 81.

When the lowermost piece of work W. is grasped by the grippers 45 and is forcibly removed horizontally and in the direction of the arrow at in Fig. '7, the arms 80 move yieldingly downward to permit such removal and at the same time the arms 85 swing downward to permit release of the next higher piece of work W which then rolls downward into feeding position.

The arms 85 are extended beyond the shaft 86, as indicated at 90 in Figs. '7 and 8, to provide stop portions which are raised as the arms 85 are depressed, thus preventing downward movement of the next higher piece of work W and thus preventing the releasing and advancing of more than one piece of work from the arms 85 to the arms 80. It will be noted that the lowermost piece of work W is substantially spaced from the next higher piece of work W, thus permitting the grippers 45 to readily engage the'work.

While the vertical bearing 41 for the plunger 43 is fixed to the carriage 23, the bearing 40 for the plunger 42 is mounted to swing about the axis of the cross shaft 49. The operating cylinder 53 is mounted to move with the bearing 40, while the cylinder 60 is fixed relative to the carriage 22. V

A stop 92 (Figs. 3 and 6) is fixed in a bracket 93 mounted on the upper edge of the frame 20 and adjustable longitudinally thereof.

The discharge runway 14 (Figs. 1 and 6) is pro-' vided with receiving arms 100, pivoted at 101 on the upper end of the runway 14 and having a pin and slot connection with a piston rod 102 operated by a piston 103 in a cylinder 104 mounted beneath the runway 14.

Fluid under pressure is admitted through a pipe 105 provided with a valve 106 connected by a link 107 to a lever 108. The lever 103 is pivoted at 109 on the runway 14 and is provided with a roll 110 at its upper end, engaged by the gripper head 65 as the unloading grippers 44 are swung to the position shown in Fig. 6. Such engagement causes the lever 108 to act through the link 107 to open the valve 106 and admit air to the cylinder 104, thus raising the arms 100 into position to receive the work W when the grippers 44 are open to release the finished work. The work then rolls down the arms 100 to the runway 14, from which it is delivered to any desired discharge position. A spring 111 assists in returning the arms 100 to normal inoperative position.

A stop 112 (Fig. 1) on the swinging bearing 40 engages a fixed shoulder 113 on the carriage 22 and limits the downward swinging movement of the bearing 40 and of the unloading mechanism supported thereby.

Having described the details of construction of our improved feeding mechanism, the method of operation thereof is as follows:

During the machine operations on the work (supported by the centers and 121 shown in Fig. 2), the plungers 42 and 43 will be in raised position. After a piece of work W is finished, air or other fluid is admitted through the pipes 54 and 61 (Fig. 1) to the cylinders 53 and 60. The plungers 42 and 43 and the grippers 44 and 45 are moved thus downward. During such move ment, the grippers are held open by their coil springs 72 (Fig. 9).

The plunger 42 continues its downward movement until the grippers 44 are positioned to close on the finished piece of work W as it is supported on the work centers. The plunger 43 moves downward until the roll '76 (Fig. 1) engages the horizontal shoulder or abutment 7'7, which acts as a stop to limit downward movement of the plunger 43 and positions the grippers 45 so that they may engage the lowermost piece of work W on the runway 13.

Fluid under pressure is then admitted through the pipes '73 to close the grippers 44 and 45 on the new piece of work W and the finished piece of work W Fluid under pressure is then applied through the pipe 55 to the opposite end of the cylinder 53, raising the plunger 42 to its uppermost position.

Fluid under pressure is then admitted through the pipe 31 (Fig. 3) to the cylinder 25, rotating the shaft 28 and gear 29 and causing the carriage 22 to be moved to the right.

During such movement, the roll 76 prevents further downward movement of the plunger 43 until the plunger is positioned substantially over the work centers, at which point the roll 76 clears the abutment 77 and the plunger 43 completes its downward movement and brings the new piece of work W into alignment with the work centers in'the machine.

In the meantime, the movement of the carriage 22 to the right to the position shown in Fig. 6 causes the upper end of the raised plunger 42 to be engaged by the stop rod 92 previously described, which in turn causes the bearing 40 to swing about the axis of the shaft 49 to the unloading position shown in Fig. 6.

As the movement is completed, the gripper head 65 engages the roll '110 on the arm 108, which in turn opens the valve 106 and admits air to the cylinder 104. The piston 103 is thus operated to swing the arms 100 upward into workengaging position, as shown in Fig. 6.

'Pressure is then relieved in the pipes 73, allowing the grippers 44 and 45 to be opened by their coil springs 72. The new piece of work W is thus released in position for operation thereon by the tool slides 11 and 12, and at the same time the finished piece of work W is released and rolls downward along the arms 100 and runway 14 to discharge or delivery position.

The plunger 43 is then raised, the carriage 22 isshifted to the left, the plunger bearing 40 returns to its vertical position during the sliding movement of the carriage 22 and the parts are thus again in initial position.

Suitable automatic operating mechanism C (Fig. 2) may be provided for effecting all of these operations in the order indicated and in a desired timed relation. Such control mechanism may be of any suitable and convenient form and is not shown in detail herein as it forms no part of our present invention.

In Fig. 10 we have shown our invention in a somewhat modified form which permits the feeding movements to take place longitudinally instead of transversely of the machine. This form of our invention has definite advantages where space at the sides of the machine is closely limited.

The work feeding mechanism is shown in Fig. 10 as mounted on a carriage 120, slidable axially of the machine on a frame member 121, which frame member is supported at one end on the head-stock 122 and at the other end on the tailstock 123. Preferably the frame member 121 will be made extensible, so as to adapt the device for use with the head and tail-stocks in different relative positions.

The work-handling and work-feeding mechanism is substantially the same as that previously described. New blanks are received from a chute or runway 125, preferably mounted above the tail-stock 123. The lower limit of movement of the loading gripper head 130 is determined by a roll 131, which engages a fixed flange or shoulder 132 on the frame 121. The head 130 is maintained in partially lowered position by the engagement of the roll and flange until the head has been moved axially over the position for delivering work between the work centers. At this point the roll 131 passes beyond the end of the shoulder 132, and the head 130 descends, presenting the work between the head and tail centers. I

The unloading head hi0 has straight vertical and horizontal movements only and delivers the finished work to a chute or runway 142, preferably mounted above the head-stock 122. The work is delivered to the chute 142 by a straight downward movement and no lateral swinging movement of the unloading head is necessary with this form of our invention.

The mechanism on the carriage and frame 121 for giving the work-heads their operative movements is substantially the same as previously described and a standard mechanism may be readily installed for either longitudinal or transverse movements.

While we have shown and described workgrippers, it is obvious that other forms of workengag ng members may be utilized.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what we claim is:--

1. Work-feeding mechanism comprising a pair of work grippers, means to open and close said grippers, separate means to give said grippers vertical and horizontal movements, and additional direct-acting means effective to interrupt the downward movement of said grippers and to prevent completion of said downward movement until a horizontal movement to a predetermined position has taken place.

2. Work-feeding mechanism comprising work: engaging unloading members, means to raise and move said unloading members to delivery position, delivery arms, and means to move said arms into position to receive the work as said members approach delivery position, said means being 'operably controlled by said members.

3. Work-feeding mechanism comprising workengaging unloading members, means to move said unloading members to delivery position, a delivery device, fluid-operated means to move said delivery device to a position to receive the work, and a control device for said latter means, operated by engagement by said unloading members as said members approach delivery position.

4. Work feeding mechanism comprising workloading members, work unloading members, a carrier for said members, separate means to give said members independent straight-line vertical upward and downward movements on said carrier, means to move said carrier horizontally, and additional means to swing the unloading members to delivery position during the final part only of said horizontal movement.

5. Work-feeding mechanism comprising a frame, a carriage, means to slide said carriage on said frame, work-engaging unloading members, a plunger supporting said members, a bearing member for said plunger pivoted on said carriage, and a stop on said frame engaged'by said plunger as said carriage is moved on said frame, whereby said plunger is given a swinging movement.

6. The combination in work-feeding mechanism as set forth in claim 5, in which the stop is mounted on a bracket which is adjustably secured to said frame.

7. Work moving mechanism comprising workengaging unloading members, means to give said members an upward straight-line movement, means to thereafter give said members a horizontal straight-line movement, and additional means to give said members a final swinging movement to unloading position as said horizontal movement is being completed.

8. Work feeding mechanism for rotated work comprising work-engaging members, means to give said members substantially vertical upward and downward straight-line movements, additional means to give said members substantially horizontal straight line transfer movements, all of said vertical and horizontal movements being in directions substantially perpendicular to the axis of the work, and a separate device effective to interrupt the vertical downward movement of said members at an intermediate point in their downward travel until after a substantial horizontal movement thereof has taken place.

9. Work feeding mechanism comprising worken'gaging members, means to give said members downward, upward and horizontal movements in predetermined order and all in directions substantially perpendicular to the axis of the work, and a separate device effective to prevent completion of the downward movement of said members until a horizontal movement to a predetermined position has taken place.

EDWIN R. SMITH. WILLIAM J. PEARSON. 

